The Puerto Rican singer, who received Spanish citizenship four months ago, speaks in the interview about Spain's law authorizing same-sex marriage, which is being challenged before the Constitutional Court.
"If they touch" that legislation, he said, "now, as a Spanish citizen, I would stand up and unite with my community."
In the interview, which appears in the April issue of Vanity Fair, the global superstar explains how he selected the egg donor for his song and rejects the expression "womb for rent."
"I saw the photo and I said to myself: Who is this woman, so angelic, so transparent? I did not rent a womb. The fundamental conservatives use that expression. They loaned me an abdomen. I didn't pay for it," the singer confesses, adding that "I would give my life for the woman who helped me bring my sons into the world."